The present invention relates to grounding apparatus for electrical fixtures and especially such apparatus which affixes directly to the electrical fixture without modification thereof. Hitherto, many different devices have been utilized to provide a grounding path between an electrical fixture and its mounting box. The most conventional approach has been to establish this path with a bonding jumper which requires that a wire be attached to both the electrical fixture and the mounting box for providing an electrical interface therebetween. This approach is very time consuming and even where sufficient time has been allotted for the incorporation of the bonding jumper, it is inadvertently disregarded on occasion to thereby result in a hazardous condition.
Another approach is to establish the grounding path by abutting the mounting yoke of the electrical fixture directly against the mounting box to achieve a metal-to-metal surface contact therebetween. Such a metal-to-metal abutment is not possible in all mounting arrangements between electrical fixtures and mounting boxes and therefore, this approach is limited to particular applications. It is also true, that the contact resistance resulting at such an abutment between surfaces is very susceptible to drastic increases from adverse circumstances and therefore, the reliability of the grounding path established thereby is very low.
Specially configured metallic clips are utilized in some applications to establish the grounding path. Disadvantages accompanying the use of these clips to achieve a low resistance grounding path between the electrical fixtures and the mounting box. One such clip is that disclosed in U.S. Pat. No. 3,432,793 which is fixedly attached to the electrical fixture and exerts a spring bias against the mounting screw. Being fixedly attached, this clip can only be utilized if the electrical fixture is modified, therefore, it increases manufacturing costs appreciably and can not be applied directly to conventional electrical fixtures. Another such clip is that disclosed in my U.S. Pat. No. 3,663,919 which presents a protruding member to be forcibly wedged between the electrical fixture and the mounting box. Although this clip is highly regarded for its intended purpose, once it is installed, the electrical fixture becomes more difficult to remove from the mounting box and thereby may present a problem during maintenance.